president obama and mitt romney squared off for the first of three presidential debates last night. in what some are calling a polite war of words, the candidates sparred over job creation, taxes and the future of health care. nbc's tracie potts is in denver for us. she has a preview. good morning to you, tracie. >> reporter: lynn, good morning. the pressure was on for romney to perform, to back up his ideas with details, taking on the man that even republicans called one of the most skilled debaters in modern politics. the point of this debate was to make differences clear on lowering the debt. >> you said you'd cut the deficit in half. it's four years later, we still have trillion-dollar deficit. >> the way we do is for additional cut, we ask for a dollar of additional revenue, paid for, as i indicated earlier, by asking those of us who have done very well in this country to contribute a little bit more to reduce the deficit. >> reporter: the president insisted romney would spend $5 trillion on tax breaks favoring the wealthy. >> math, common sense and our history shows us that's